An organic light emitting phenomenon denotes a phenomenon where electrical energy is converted into light energy by using an organic material. That is, in a case where an organic material layer is disposed between an anode and a cathode, when a voltage is applied between the anode and the cathode, the anode injects a hole into the organic material layer, and the cathode injects an electron into the organic material layer. The hole and the electron which are injected into the organic material layer are combined to generate an exciton, and when the exciton is shifted to a ground state, light is emitted.
Since an interval between the anode and the cathode is small, an organic light emitting device is easy to have a short circuit defect. Due to a pin hole, a crack, a step in a structure of the organic light emitting device, and a roughness of coating, the anode may directly contact the cathode, or a thickness of an organic material layer may be further thinned in those defect regions. The defect regions provide a low-resistance path in order for a current to flow, thereby allowing the current to hardly flow or allowing the current not to flow through the organic light emitting device at all in an extreme case. For this reason, an output of light emitted from the organic light emitting device is reduced or removed. In a multi-pixel display device, a short circuit defect causes a dead pixel which does not emit light or emits light having a light intensity less than an average light intensity, causing the degradation in display quality. For illumination or a low resolution, a large portion of a corresponding region cannot operate due to the short circuit defect. Due to concern about the short circuit defect, manufacturing of the organic light emitting device is conventionally performed in a clean room. However, the short circuit defect cannot be effectively removed even in a clean environment. In many cases, in order to decrease the number of short circuit defects by increasing an interval between two electrodes, a thickness of the organic material layer more increases than a thickness actually necessary for operating a device. Such a method additionally increases the manufacturing cost of the organic light emitting device, and moreover, cannot completely remove the short circuit defect.